Very interesting. Since “pizz” in a string part couldn’t mean anything but pizzicato (pizza? not likely) it’s just as obvious with no period. Also “arco” is not abbreviated, so that makes more of a “parallel construction”. I guess they were saving space, and a bit of work.

I've long felt that abbreviation dots have little real function except where their absence might cause confusion, which is clearly not the case with 'pizz'. I rarely use them in my MS scores, but I do in Finale, for no better reason than that they're there by default.

According to a very knowledgeable lexicographer with whom I'm acquainted, the UK practice for their use in English is much more relaxed and flexible that is that of the US, which is stricter and more traditional.

I'm not sure, though, how this might relate to a French publisher of a century ago!

Yes, now that you mention it, for years I have felt more comfortable with the British way of writing St for Street, Mr for Mister, etc, with no periods. (And yet I’m not in the habit of writing “etc.” without one! Had to change it to be self-consistent.)